Email list groups created in Google Groups are different from the contact groups you can create in your My Contacts (Contacts in Google Mail).
The primary difference is that a contact group is for your personal use, while a Google Group can be used by more than one person (because it has its own email address, so it can be shared in the Groups directory (if selected) and others can send messages to it; contact groups don’t have their own email address, so no one else can send messages to them).
Thus, if Bob and Mary both need to contact the same group of people, they should create a Google Group Email List rather than creating and managing two separate personal contact groups.
Here’s a summary of differences between Contact Groups and Google Groups:
|Personal Contact Group||Google Group Email List
|Only group owner can use||Group managers, members, and/or campus community can use|
|Created through Contacts||Created through Google Groups.
Will create an email address for the group
|Managed through Contacts||Managed through Groups|
|Can share docs and sites with group|
Cannot share calendars
|Can share docs, sites and calendars with group|
|Recipients see email in inbox only||Recipients can see email in inbox, through the online forum, or both|